Self-opening closure



Aug. l, 1950 N. B. WALES SELF-OPENING cLosuRE 2 Sheets-Sheet 1 Filed March 51, 1947 FIG.\

Aug. 1, 1950 N. a. wALEs SELF-OPENING CLOSURE 2 Sheets-Sheet 2 Filed March 3l, 1947 IN VEN TOR. W

Patented Aug. 1, 1950 SELF-OEENING CLOSRE fNathaniel B. Wales, New York, `N. Y., assignor to Industrial lPatent Corporation, New York,

Application March 31, 1947, Serial No. 738,296

Claims. vlr

This invention relates to self-opening containers, or what is commercially known as tin cans, and is an improvement and a continuation in part of my pending United States Patent application Serial Number 578,451, now Patent No. 2,449,186.

Whereas in the above mentioned patent application I employ a collapsed chamber in which I insert a gas generating substance which generates apressure when subjected to heat, exterior to theactual double folded seamwhich forms the) hermetical seal between the container and the top or closure of the container, I now insert a gas generating substance, which in this case has `explosive or rapid burning characteristics within the `double folded seam which now constitutes the collapsed chamber. U `In this manner advantage is taken of the conventional production technique and machine equipment as is now in use in can-manufacturing to carry out the basic theme of my invention, which is the inflation of a collapsed chamber to release `the closure from the container.

.Itl is, moreover, conventional to insert within the inner fold of the double folded interlocking seam as above described a fluid rubber compound to insure the hermetical seal essential between the closure and the container. I therefore may add to this rubber compound a relatively low ignition temperature explosive or an explosive compound having viscous characteristics may be used alone. v

In close, proximity tothe double folded interlocking seam securing the closure to the container I form a circumferential scored section oneitherthe container or the closure so that by theinflation of the collapsed chamber in the seam by the pressure wave generated therein the scored section of metal will sever and release the closure from the container. l

This objective maybe accomplished in several modifications of structure which are disclosed herewith.

Other objects and details will be more specifically described in the following `specifications and drawings in which:

Figure 1 is a side View in elevation of a container embodying the invention, the upper p0rtion of which is shown in section.

Figure 2 is an enlargement of the double seam as shown in Figure 1 taken on line A-A.

Figure 3 is the same section as shown in Figure `2 as it would appear after it has undergone ination due to the ignition of the gas generating sub- 2 stance incorporated within the double folded seam during fabrication.

Figure 4 is an enlarged section similar to Figure 2 except that it shows a modification of the anvil or` stiiened section of the body of the container in close proximity to the scored ring in the body of the container.

Figure 5 is an enlarged view in section taken on line A-A in Figure 1 of a modification of the disposition of the double folded interlocking seam between the closure and the container, also a modification of the position of the circumferential scored ring in respect to the seam.

Figure 6 is the same enlarged view as is seen in Figure 5 but indicating the position of the seam after being dilated by the ignition of the explosive substance incorporated therein.

Referring more specifically to the drawings similar numerals refer to similar parts:

Numeral I is the body of the container, 2 is the closure which is conventionally secured to the container body by the double folded seam 3.

, Considering the double folded seam 3: the top end of the container body I appears in the double fold at 4 whereas the inner fold 5 of the metal of the closure 2 is wrapped around member 4 in such a manner as to leave a circumferential cavity 6 therebetween. This cavity 6 contains the explosive or gas generating substance I3, which is so compounded and proportioned that when it is ignited by the application of heat, as from a match 1, the ensuing pressure generated dilates the cavity E as seen in Figure 3.

Itis to be noted that as cavity 6 is inflated the `fold 5 in expanding inwardly presses against the contacting face of the container wall section 8 assisting in the pressure seal therebetween and forcing the wall of the container inwardly as seen in Figure 3. However in distorting the metal of this section of the container inwardly at a typical `segment of the container I as enumerated at 8 the circumferentially scored ring I0 ruptures and the closure 2 together with the inflated double folded seam 3 are separated from container I.

In order to focus the inward thrust of the expanding seam 3 due to its Contact with the wall of container I on to the scored ring IIJ in container I a, stiffened section II of the container I, which may be produced by beading the metal, or the like, is positioned in close proximity to the scored section I0 in container I. This beading acts as an anvil and focuses the distortion of the wall of the container I on to the weakened section ofthe container wall as denedby the scored ring Ill.f t l the body of the container i and thus be of the seam and the position of the scoring as isA shown in Figures 5 and 6. The gas generating substance i3 may be stenciled or coatedon` the surface I4 of the closure 2 prior to the foldingof against deformation, an explosive substance incorporated within said seam, the ignition of which inates said seam thereby deforming the lwall of said container above said bead to that extent suicient to cause severance along said scored section.

2. An hermetical closure fora container adaptfed tobe self-opened bythe lapplication of heat within saidseam, a `circumferential scored secthe closure into the doublefolded seamA 3, which is analogous to the application of the viscous r can manufacture rubber compound now used in as previously described.

The annular scored ring section l 5 is now posi-,

tioned in the closure Zat a point where itismsubject to a high disruptive force which is a componentof the innation of the chamber f6. Pis the chamber IG is formed by vthe pressure wave resulting from the ignition of substance i3 the sheet metal member il is drawn downward towards the expanding chamber 6 causing the closure 2 to rise due to the metal portion IS slipping around the curvature Il? of seam 3, and this downward pressure further iiexes the scoredt ring l5; "in this manner by the combined tension and iiexation which the scored section I5 undergoes itis severed and the closure 2 is released from Vthe container.

A further force resultant tendingto eject the severed closure 2 "from the body'of the container I resides in the fact that the explosive substance !3 is positioned substantially in the ybase of the seam 3 and the maximum distension of seam 3 wouldy occur substantially as indicated. Therefore the wall Zll of the container opposite` the seam 3 would exert an upward force component on the closure 2. f l v It is evident to those skilled in the art that the seam 3 might be positioned in a different plane, 'as for example, if the axis of the container of which only a fragment is shownin Figure 4 is" the line B-B the double folded seamy 3 instead of being in a plane parallel' to the axis B-B, as isA seen in Figure 5 might extend outwardly from at. right angles to the line B-B.

The basic concept of this invention is the utilization of the conventional multi folded seam which forms a hermetical seal between the closure and the container as a collapsed chamber and. by inserting a, gas generating substance v ytherein the resultant dilation of the seam is harnessed to sever the closure from the container. This concept results in a low cost embodiment of my invention since only a, slight alteration .of existing standard fabrication procedure in tin can manufacture isnecessary to achieve the desired result.

er below said scored section and adjacent therej to adapted to stiifen the wall of said container tion formed in said container in close proximity to said double,l folded seam, a circumferential bead formed in the wall of said container below said scored section' and adjacent thereto in order to vstiffen the wall of said container against deformation whereby on the infiation of said seam by the ignition of said explosive therein the wall of said container is deformed above said bead to that extent sufficient Vto cause severance along said scored section.V

3. Hermetical sealing means forl a container adapted' to self-open by the application of heat thereto comprising a closure, a plural folded seam securing" the periphery of said closure to one end of said container,` a circumferential scored' section formed in said container in close proximity to said seam, stiffening means incorporated in said container adjacent to and below said circumferential scored section, an ignitable gas generating substance positioned within one of the folds ,of said seam in order to inflate said seam when ignited bythe application of heat thereto and by said inflation to sever said scored section in said container.

4. Hermetical sealing means for a container adapted to self-open by the application of heat thereto, comprising a closure, a plural folded seam securing theI periphery ofsaid closure to one end of said container, a circumferential scored section formedin said closure in close proximity to said seam, an ignitable'gas generating substance positioned 4within one of thefolds of said seam in order to inflate said seam when ignited by the application of heat thereto and by said inflation to sever said scored section in saidI closure.

5. Hermetical sealing means for a container adapted to self-open by the application of heat thereto, comprising a closure, a plural folded seam. securing the periphery of said closure to one end of said container, a circumferential scored section'formedv4 in said closure in `close proximity to and above said seam, an ignitable gas generating` substance positioned within one of the folds of `said seam in order to inflate said seam when ignited lby the application of vheat thereto and by said ination to sever said scored section in said closure.

' NATHANIEL B. WALES.

REFERENCES CITED "The following references are of record in the file of this patent:A f

UNITED STATES PATENTS Norway Oct. 5, 1931 

